response小结（四）

1.发送http头，控制浏览器定时刷新网页（REFRESH）。

 package com.yyz.response;
 
 import java.io.IOException;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 //定时刷新
 public class ResponseDemo extends HttpServlet {
 
    public void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         response.setHeader("refresh", "5");
         response.setContentType("text/html;charset=UTF-8");
         response.setCharacterEncoding("UTF-8");
         response.getWriter().write("我是一个中国人！");
 }
     public void doPost(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
            doGet(request,response);
     }
 }

2.发送http头，控制浏览器禁止缓存当前文档的内容，通过下面三个消息头均可，但不同的浏览器支持不同的设置方式，所以开发中一般三句都写:

response.setHeader("Expires", "-1");
     response.setHeader("Cache-Control", "no-cache");
     response.setHeader("Pragma", "no-cache");